| 摘要 |
PURPOSE:To facilitate the change in the boosting ratio of a brake booster, by providing a hollow expansible/compressible member between a housing and the push rod of a master cylinder and altering the internal pressure of the member to change the boosting ratio. CONSTITUTION:A hollow expansible/compressible member 22 is provided around a push rod 16 in a constant pressure chamber 5. One end of the member 22 is gas-tightly secured on a housing 2, while the other is gas-tightly secured with a bearer plate 24 on the push rod 16. The chamber 25 of the expansible/compressible member 22 is connected to a changeover unit 30 through a hole 27, a vortical pipe 26 and pipes 28, 29. The constant pressure chamber 5 and a changing pressure chamber 6 are also connected to the changeover unit 30. The chamber 25 of the member 22 is connected to the constant pressure chamber 5 or the changing pressure chamber 6 by operating the knob 52 of the changeover unit 30. When the chamber 25 is connected to the constant pressure chamber 5, the ratio of boosting is increased. When the chamber 25 is connected to the changing pressure chamber 6, the ratio of boosting is decreased. |
